well I read some of the spoilers... but I doubt he is really gone for good. I read one where it almost hints as much to the audience. I saw the pics back when, but those were just concept pics.
I still think, regardless of what it looks like at the end of the movie, he will be back. I mean how else can you reverse the supposed ending of the movie if it is not by having a huge return of him which coincidentally clears the whole situation up (sorry to be vague, but trying not to spoil)... as much as I like them, I don't think Riddler or Catwoman would fit that role and I know anyone smaller is even less likely to.
Besides, I thought they signed Eckhart to a 2 movie contract for Batman... why the second if he is not going to be in it?